Hydraulic strain-equalizer



' W. C. BECKWITH.

HYDRAULIC STRAIN EQUALIZER.

APPLICATION FILED NOV. 4. 1918.

Patented July 22, 1919.

3 SHEETS-SHEET L WMKAQ UMBIA PLANOORAPII 50., WASHINGTON. D. C.

I W.C.BEC KWITH.

HYDRAULIC STRAIN EQUALIZER. APPLICATION FILED NOV. 4'. 1918.

Patented July 22, 1919.

3 SHEETS-SHEET 2.

avwemtoz Z W m, um (46a 1 1 momma 'lllE COLUMBIA PLANOGRAIH co, WASHINGTON. n. c.

.. described and ,'in part obvious as WALTER C. BECKWITH, OF FCSTORIA, OHIO.

HYDRAULIC STRAIN-EQUALIZPR.

To all whom it may concern Be it known that I, WVALTER C. BnoKwrrH, citizen of the United States of America, residing at Fostoria, in the county of Seneca and State of Ohio, have invented certain new and useful Improvements in Hydraulic Strain-Equalizers, of which the following is a specification. r

The present invention relates to hydraulic strain equalizers and has for its object to provide a simple and effective means for equalizing or relieving the strain on lifting and hauling cables or analogous flexiible means.

' Considerable difliculty has been experienced in raising sunken vessels due to the fact that the cables employed were incapable of withstanding the strain placed upon them, it frequently happening that where one cable was subjected to a greater strain than the others, it would snap thus throwing an added weight upon the others with the result thatthey would all give away. This is obviated by my invention.

Other. and further objectswill be in part the speci fication is proceeded with In the accompanying drawings forming part of this'specification:

. my invention attached showing its use in connection with the salvaging of sunken vessels; n q A Fig. 2 is a sectionon the line 33 Fig. 3 showing the hoisting apparatus and connections;

Fig.3 is a side-view partly in section of my invention; i

Fig. 4 is a modified form of my inventlon; and l 1 4 Fig. 5 is a further modificationthereof in sectional elevation.

V Referring moreparticularly to the drawings in which like reference-numerals refer to corresponding parts throughout the several views, 1 denotesa ship mounted upon the deck 2 of which is a plurality of hollow ends of the stems carrying pulleys 1O axially Specification of Letters Patent.

' AppIication filed November 4, 1913.

Figure 1 is a side view of a ship having.

Patented July 22, 1919.

Serial No. 261,096.

alined therewith for a purpose to be decommunicating with the chamber 6 and at their upper ends are closed by threaded caps 13 similar to the caps 7. Stems 14: having angled ends 15 pass through the caps 13 and carry at their lower ends what may be termed auxiliary pistons 16, the latter being normally seated to close the openings 12 by means of coil springs 17 bearing at opposite. ends against the cap 13 and piston 16 respectively. Thetension of these springs may be readily adjusted by screwing up or unscrewing the caps 13 as desired.

WVhen the chamber 6 is filled witha suitable liquid, preferably heavy oil, and the cylinders5 and 11 partially filled as inclicated in Fig. 2, any downward pressure upon the stems 19 tends to force the piston 16 and its stem upwardly in an obvious manner. This upward movement of the piston 16 is resisted by the spring 17 which is, of sufficient strength-to overcome a predetermined pressure of say twenty five tons.

In the embodiment of the invention illustrated I have shown its application to the art of raising sunken vessels. In Figs, 1 and 3, 18 are cables which pass over the pulleys 10 on the piston stems 9 and are connected at one end as at 19 to the vessel 20 to be raised and at the other end to the drum 21 of a hoisting apparatus 22. The drum 21 may be manually operated by means of gears 2324: and crank handle 25 for the purpose of drawing the cables taut, but the lifting operation is effected by any suitable power plant such as a steam, electric or gasolene motor 26. a As the hoisting apparatus andpower drivingmeans and connections may be of any approved type further detailed descriptionthereof is deemed unnecessary. It will of course be understood that there will be as many power plants as base plates or units 3. When either of the cables 18 of any pair is placed under a greater strain than twenty five tons the stem. 9 and piston supporting the cable will be correspondingly depressed and automatically relieved by its companion cable due to a corresponding elevation of the piston and stem supporting the said companion cable until such time as both cables come under the maximum strain of twenty five (25) tons. When a maximum strain of twenty five (25) tons is placed on both cables the pressure exerted by the fluid against the bottom of piston 16 elevates the latter and shuts off the power plant and consequently stops the winding drum 21 whereupon the lifting operation is halted and all strain on the cables 18 relieved in the following manner.

Each cylinder 11 is provided with a strap 27 encircling the same which supports a bell crank lever 28 one arm of which is connected by a link 29 to the angular end 15 of the stem 14 while the other arm of the bell-crank is connected by a rod 30 to a lever 31 in turn adapted to stop and start the power plant 26 through the medium of a valve or switch (not shown).

Disconnection of the power plant is effected through the mechanism just described by the elevation of the piston 16 and its stem 14 while the lowering of the piston 16 and its stem, operates the valve Or switch (not shown) to start the motor and the winding drum.

In the modification illustrated in Fig. 4 I employ a solid base plate 32 secured to the deck 2 of the ship 1 by means of bolts 4. The plate 32 supports or has cast therewith a horizontally disposed cylinder 33 closed at one end by a threaded cap 34 through which extends a piston rod 35 carrying at one end a piston 36. The opposite end of the rod or stem carries a pulley 37 and is pivoted to a bracket 38 slidably mounted in a plate 39 secured to the base plate 32 by bolts 40. It will be understood that the cylinder 33 contains a heavy fluid such as oil 45.

The cylinder 33 is formed with a small tubular extension or neck 41 communicating at its inner end with the interior of the cylinder and closed at its outer end by a threaded plug. or closure member 42. A piston stem 43 carrying a piston 44 extends through the cap and connects at its outer end with the rod 30 leading to the power plant 26. A coil spring 46 bears at opposite ends against the closure member 42 and the piston 44 and normally tends to maintain the piston 44 in the position illustrated in the drawing. The operation is as follows:

The tension of spring 46 is regulated by means of the screw plug or closure 42 to overcome a pressure of say twenty five (25) tons and when the pressure exerted by the cable 18 passing over drum 21, pulley 37 and idler pulley 47 exceeds twenty five (25) tons the piston 36 is forced in the direction of the arrow, the pulley 37 and sliding bracket 38 of course moving simultaneously therewith. This movement of the piston 36 causes the piston 44 to overcome the tension of the spring 46 and to move with its stem 43 in the direction of the arrow. This movement of the stem 43 is communicated through the rod 30 to the lever 31 thus stopping the power plant and the winding drum 21 and thereby relieving the pressure on the cable 18. As soon as the pressure drops below twenty five (25) tons the movement of parts just described will be reversed and the power plant will be automatically started and the lifting operation will. continue.

The modification shown in Fig. 5 comprises a base 48 adapted to be secured to the deck of a ship by bolts or the like 49. A pair of vertically disposed cylinders 50 and 51 cast integrally with the base 48 are connccted at their lower ends by a' valved pipe 52. The upper ends of the cylinders are closed by a cap 53 and screw plug 54 respectively. The cylinder 50 is partly filled with heavy oil. and'contains a piston 55 the stem 56 of which projects through the cap and carries a pulley 10 similar to that shown in Figs. 1, 2 and 3. A piston 57 operating in the cylinder 51 has a stem 58 passing through the plug 54 provided with an angular end similar to the end 15 of" the piston 14 Figs. 1, 2 and 3. This angular end of the stem 58 is connected to the power plant in the identical manner illustrated in the preferred embodiment of my invention. A coil spring 59 surrounds the stem 58 and bears at opposite ends against the plug 54 and piston 57 normally holding the latter in the lowermost position illustrated.

In practice the tension of coil spring 59 is adjusted by means of the plug 54 to overcome a pressure of twenty five tons exerted against the bottom of piston 57 when the valve 60 has been opened a predetermined distance.

WVhen the cable 18 is put under a strain exceeding that of twenty five (25) tons the stem 56 and piston 55 will be depressed, thus forcing the oil in cylinder 50 and pipe 52 through the latter against the bottom of piston 56 elevatin the latter and effecting the stopping of t e winding drum in the manner herein described.

Having thus described my invention, what I claim is:

1. A device of the type" described, including opposed pistons, cables controlled by said pistons for lifting heavy bodies, an auxiliary piston, means providing communication between the containing chambers of said pistons, said chambers being supplied with a liquid, resilient means provided within the auxiliary piston-chamber for opposing the pressure of fluid on said auxiliary piston, and means controlled by said auxiliary piston for limiting the pull which the hoisting means may exert upon any given set of cables.

2. A device of the type described, includthe hoisting means may ing hydraulic pistons, cables controlled by said pistons for lifting heavy bodies, an auxiliary hydraulic piston, means providing communication between the containing chambers of said pistons, said chambers being supplied with a liquid, resilient means provided within the auxiliary piston-cham ber for opposing the pressure of fluid on said auxiliary piston, and means controlled by said auxiliary piston for limiting the pull which the hoisting means may exert upon any given set of cables, comprising an automatic cut off and connections between the same and the auxiliary piston.

3. A device of the type described, including opposed hydraulic pistons, cables controlled by said pistons for lifting heavy bodies, the rods of said pistons being equipped with rotary members over which are passed said cables, an auxiliary hydraulic piston, means providing communication between the containing chambers of said pistons, said chambers being supplied with a liquid, resilient means provided within the auxiliary piston-chamber for opposing the pressure of fluid on said auxiliary piston and means controlled by said auxiliary piston for limiting the pull which exert upon any given set of cables. 1

4:. A device of the type described, including opposed pistons, cables controlled by said pistons for lifting heavy bodies, an auxiliary piston, a base member afli'ording communication between the containing chambers of said pistons, said piston-containing chambers and said base-member providing for containing the piston-compressed liquid, resilient means provided within the auxiliary piston chamber for opposing the pressure of fluid on said auxiliary piston and means controlled by said auxiliary piston for limiting the pull which the hoisting means may exert upon any given set of cables.

5. A device of the type described, including a piston, a cable controlled by said piston for hoisting heavy bodies, an auxiliary piston, means providing communication between the containing chambers of said pistons, a body of liquid being provided intermediate of, and in contact with said pistons, and automatically controlled means controlled by said auxiliary piston for limiting the pull which may be exerted on the hoisting cable.

In testimony whereof I aflix my signature in presence of two witnesses.

WALTER O. BECKWITH.

Witnesses:

EDNA JAMES 'SHEEHY, K. T. Mints.

copies of this patentmay be obtained for flvecents each, by addressing the "commissioner of Patents, Washington, D. G. 

